Self-supporting blast furnace shell and metallic lining for blast furnace

ABSTRACT

A one-piece, integral blast furnace shell, the totality of which is self-supporting and which extends continuously, without interruption from the top of the stack to the bottom of the hearth. No mantle; no columns. A fluid-cooled internal metallic lining for a blast furnace. The lining extends continuously, without interruption, and without sharp angular changes, from the top of the stack to the lower part of the bosh. The lining is movably mounted to accommodate thermal changes in furnace.

United States Patent Inventors Lawrence G. Maloney Munster; WilliamEJSlagnley, Crown Point, both oi Ind. Appl. No. 750,968 Filed Aug. 7,1968 Patented Nov. 30, 1971 Assignee Inland Steel Company Chicago, Ill.

SELF-SUPPORTING BLAST FURNACE SHELL AND METALLIC LINING FOR BLASTFURNACE 12 Claims, 14 Drawing Figs.

US. Cl 266/25, 266/32 Int. Cl C2lb 7/00 Field of Search 266/25. 32.

43, 27, 29,31, 17; 263/29; 1 l0/l A [56] References Cited UNITED STATESPATENTS 1,792,614 2/1931 Stern 266/25 X 2,339,192 1/1944 Roberson 266/252,770,451 11/1956 Almond 263/29 3.371918 3/1968 Ueshima et a1.. 266/433,431,691 3/1969 Greaves et a1. 266/25 X FOREIGN PATENTS 471 ,973 9/1937Great Britain 1 10/1 A Primary EkamineF-Gerald A. Dost Attorney-Merriam.Marshall, Shapiro & Klose ABSTRACT: A one-piece, integral blast furnaceshell the totality of which is self-supporting and which extendscontinuously, without interruption from the top of the stack to thebottom of the hearth. No mantle; no columns.

A fluid-cooled internal metallic lining for a blast furnace. The liningextends continuously, without interruption. and without sharp angularchanges, from the top of the stack to the lower part of the bosh. Thelining is movably mounted to accommodate thermal changes in furnace.

SELF-SUPPORTING BLAST FURNACE SHELL AND METALLIC LINING FOR BLASTFURNACE BACKGROUND OF THE INVENTION Conventional blast furnaces have asteel outer shell and an inner refractory lining. The furnace and theshell comprise, in vertically descending sequence, a stack section, abosh section and a hearth section. Tuyeres, located around the peripheryof the furnace, extend into the furnace interior at the top of thehearth section to provide combustion gases such as air to the furnaceinterior. A superstructure, including apparatus for introducing chargingmaterial into and exhausting gases from the top of the blast furnace, isgenerally located above and supported atop the stack section of theshell.

The stack section has by far the largest vertical dimension of any ofthe shell sections, and, conventionally, the stack section is supportedindependently of the lower bosh and hearth sections by a ringlike mantleoffset from the lower shell sections and underlying the stack sectionand its refractory lining. The mantle is located at the junction of thestack and bosh sections, although, conventionally, these two sectionsare not jointed. The mantle is supported by a plurality of columnsresting on a relatively massive foundation extending downwardly from thefloor of the furnace cast house or from grade.

The conventional blast furnace shell and supporting structure have anumber of drawbacks. For example, the mantle is a thick, cumbersomestructure which introduces special stress, cooling and refractoryproblems at the junction of the stack and bosh sections and whichrequires special expansion joints at this junction.

The presence of the mantel-supporting columns restricts the furnacedesign in such design areas as the number and spacing of tuyeres, thelocation of cinder and iron notches in the furnace, the arrangement ofrunners leading from the furnace for carrying away slag and molten iron,and the location of various auxiliary equipment. Because of the columns,the tuyeres cannot generally be located symmetrically around thefurnace. Moreover, the columns reduce the working space and causecongestion around the lower part of the furnace; the columns limitaccess to portions of the hearth section and bosh section of thefurnace; and the columns greatly limit the use of mechanized equipmentaround the bottom of the furnace, an area where mechanized equipment isgreatly needed.

Referring now to the interior of the blast furnace, for many years theinterior was lined with refractory brick in the stack and bosh sectionsof the furnace. This refractory lining was either entirely uncooled orwas cooled with conventional copper cooling plates which extendedinwardly through openings in the furnace shell and which were embeddedat spaced intervals in the refractory lining. The furnace shell openingsfor the copper cooling plates were weak spots from the standpoint ofmaintaining a gastight vessel.

More recently, the interior of the furnace, in the stack sectionthereof, has been lined with vertically stacked tiers ofcircumferentially arranged metallic cooling staves cooled by circulatinga cooling fluid therethrough. The staves are mounted on the furnaceshell inwardly of the shell and refractory material is located inwardlyof the cooling staves. The cooling staves minimize the erosion of therefractory material; and, in cases where refractory material has beencompletely worn away, the cooling staves cause tacky slag or chargingmaterial to fuse to the inner surface of the staves and provide, ineffect, a replacement refractory lining on the inside of the coolingstave.

Fluid-cooled metallic linings, composed of staves, for the stack sectionof a blast furnace are shown in Rosenak U.S. Pat. No. 3,314,668 and inZherebin et al. U.S. Pat. No. 3,379,427.

The interior furnace lines of conventional blast furnaces, includingthose with metallic cooling staves, comprise sharp angular changes atthe junction of the stack section and bosh section and again at thejunction of the bosh section and hearth section. These sharp angularchanges at the interior LII surface of the blast furnace wall causesudden changes of direction in the blast furnace charge material as itdescends from the top to the bottom of the furnace, and this is notdesirable because it increases wear on the furnace interior walls andcauses serious changes in the interior furnace lines.

SUMMARY OF THE lNVENTlON All of the above described defects inconventional blast furnace shells and in conventional blast furnacelinings are eliminated with embodiments in accordance with the presentinvention.

A blast furnace shell in accordance with the present invention isentirely self-supporting, eliminating the mantle, the mantle-supportingcolumns, the expansion joint at the junction of the stack and boshsections, and the massive foundations for supporting the columns.Undesirable stress concentrations, previously inherent in conventionalfurnaces in the area about the junction of the nonintegral stack andbosh sections, are also eliminated.

The additional space created around the outside of the furnace bottom bythe elimination of columns permits utilization of mechanized equipmentheretofore not possible and provides greater flexibility in furnacedesign and in placement of auxiliary equipment on the outside of thefurnace bottom.

The shell has an integral, one-piece construction extendingcontinuously, without interruption from the top of the stack section tothe bottom of the hearth section. This type of construction isespecially adaptable to external spray-type cooling, pennitting thespray to trickle continuously from the top to the bottom of the furnacearound the periphery of the furnace shell.

in one embodiment, the furnace is provided with stiffening rings, aroundthe shell exterior, attached to permit the shell to expand and contract,due to thermal variations during operation of the furnace, withoutpermanently distorting the furnace.

Because the furnace is of one-piece construction, gas leakage is reducedand the ventilation requirements of the furnace house arecorrespondingly reduced.

Blast furnaces are being operated at higher and higher pressures, andthe one-piece, integral construction withstands such higher pressuresbetter than do conventional furnaces provided, for example, withexpansion joints which are weak spots in withstanding leakage at highpressures.

The self-supporting shell may be lined with a conventional refractorylining without interior cooling, or it may utilize conventional coppercooling plates for cooling the interior lining, or it may use metalliccooling staves between the shell and the refractory lining with thecooling staves being constructed as previously proposed by others or asdisclosed herein in accordance with another embodiment of thisinvention.

The problems inherent in conventional interior linings and internalcooling devices for blast furnace are eliminated in accordance withadditional embodiments of the present invention.

More specifically, the present invention embodies a metallic lining forthe furnace interior which extends continuously, without interruptionfrom the top of the stack section to the lower part of the bosh sectionand which eliminates all sudden angular changes in the interior surfaceof the furnace wall. The metallic cooling staves forming the internalmetallic lining are mounted, with bolts extending through the furnaceshell, for movement relative to the shell to accommodate radiallydirected forces in the furnace interior. Effective gas seals areprovided for both the stave-mounting bolts and for cooling fluidconduits which extend from the staves through the furnace shell. Theinterior furnace lines are permanent. Conventional, erodable bricklining is eliminated in both the stack and bosh sections of the furnace.The metallic cooling staves are installed at the desired working linesof the furnace, and these lines do not significantly change.

The result is an internally cooled, gastight blast furnace havingpermanent interior lines defining a maximum internal volume and having ametallic lining defining a vertically disposed internal space withgradually changing lateral dimensions along the entire verticaldimension of the lining.

Other features and advantages are inherent in the structures claimed anddisclosed or will become apparent to those skilled in the art from thefollowing diagrammatic drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary verticalsectional view showing a blast furnace having a shell constructed inaccordance with an embodiment of the present invention;

FIG. 2 is an enlarged fragmentary sectional view taken along the line2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary sectional view illustrating lowersections of the shell;

FIGS. 4, 5 and 6 are diagrammatic illustrations of the contours of blastfurnaces having self-supporting shells constructed in accordance withembodiments of the present invention;

FIGS. 7 and 8 are fragmentary sectional views illustrating a portion ofthe wall of a blast furnace having a shell con structed in accordancewith an embodiment of the present invention, each showing a differenttype of structure for supporting a refractory lining in the stacksection of the furnace;

FIG. 9 is a vertical sectional view of the upper part of a blast furnacehaving a metallic lining in accordance with an embodiment of the presentinvention;

FIG. 10 is a vertical sectional view of the lower portion of the blastfurnace of FIG. 9;

FIG. 11 is an enlarged fragmentary sectional view illustrating theattachment to the shell of the blast furnace of a metallic cooling staveand a cooling fluid conduit for the stave;

FIG. 12 is a view from the furnace interior of a metallic lining for thebosh section of the blast furnace;

FIG. 13 is a view from the furnace interior of a metallic lining for thestack section of the blast furnace; and

FIG. 14 is a fragmentary vertical sectional view illustrating stiffeningrings for a self-supporting blast furnace shell in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring initially toFIG. 1, there is shown a blast furnace having a metallic shell,indicated generally at 10, composed of welded steel plates andconstructed in accordance with an embodiment of the present invention.Located inwardly of shell 10 is a refractory lining 11 cooled bymetallic cooling staves 17 located between shell 10 and refractorylining 11.

At the top of shell 10 is an opening 12 through which charging materialis introduced into the furnace. Seated in opening 12 is a conventionalcharging bell 13 movable vertically for opening or closing opening 12.Located around the interior of the furnace, just below opening 12, aremetallic wear plates 14 for absorbing the impact and abrasion ofcharging material introduced into the furnace through opening 12. Wearplates 14 may be constructed in accordance with structures disclosed inSlagley U.S. Pat. No. 3,202,407 or as subsequently described herein.Located just below wear plates 14 are tiers of additional plates 15constituting a stockline armor which absorbs the impact and abrasion ofcharging material descending from the top of the furnace. The stocklinearmor may be constructed in accordance with structures disclosed inMaloney U.S. Pat. No. 3,404,876.

Also located at the top of the furnace is an exhaust conduit 16 forexhausting gases from the top of the furnace.

Furnace shell 10 includes, in vertically descending sequence, a stacksection 20, bosh section 21 and a hearth section 22, all joined togetherto form an integral, continuous,

uninterrupted, one-piece blast furnace shell composed of the three shellsections 20, 21, 22. Shell 10 is entirely self-supporting with the solesupport for stack section 20 consisting of shell sections 21, 22 locatedbelow the stack section. Each of the lower shell sections 21, 22 hassufficient strength to support the shell sections located thereabove andthis strength is maintained during operation of the blast furnace, anoperation in which relatively high temperatures are generated.

In one embodiment of the present invention, lower shell sections 21, 22are provided with stiffener bars 34 (FIG. 3) spaced circumferentiallyaround the lower sections of the furnace and extending vertically fromthe bottom of hearth section 22 along the hearth and bosh sections 22,21. As shown in FIG. 3, shell hearth section 22 terminates at a bottomflange 24 secured to an underlying concrete foundation 26 by bolts 25.

Spaced around the periphery of the furnace at the top of the hearthsection 22 are a plurality of tuyeres 23 for providing combustion gas tothe interior of the fumace. In the interior of the furnace is a furnacebottom 27 composed of refractory material.

In the embodiment of FIG. 1, shell stack section 20 flares outwardly ina downwardly direction to accommodate thermal expansion of the chargematerial as it moves downwardly in the furnace. Bosh section 21 tapersinwardly in a downward direction to accommodate the decrease in volumeof the charge material as it melts; and the hearth section 22 isessentially vertical.

Shell 10 includes a first transition portion 28 located at the junctionof stack section 20 and bosh section 21, and transition portion 28gradually changes laterally along a vertical dimension at said junction.The furnace shell also includes a second transition portion 29 locatedat the junction of bosh section 21 and hearth section 22, and secondtransition portion 29 also gradually changes laterally along a verticaldimension at said junction. Both transition portions 28, 29 arecontinuous and uninterrupted. First transition portion 28, althoughlocated at the junction of the stack section and bosh section, is devoidof an expansion joint, a provision frequently utilized in conventionalblast furnaces utilizing a mantle for supporting the stack section ofthe shell.

As described above, shell 10 has opposed side walls, substantialportions of which are in nonparallel relation. Other contours, inaddition to the contour illustrated in the embodiment of FIG. 1, may beused in accordance with the present invention. Such additional contoursare illustrated in FIGS. 4, 5 and 6 depicting contours 31, 32 and 33respectively.

The sole support of stack section 20 consists of lower shell sections21, 22, and the blast furnace shell does not require and does notinclude a mantle and columns for supporting the stack section.Accordingly, all the disadvantages inherent in structures utilizingmantles and supporting columns are eliminated with the one-piece,self-supporting blast furnace shells constructed in accordance with thepresent invention.

Referring to FIGS. 1, 2 and 14, the blast furnace shell is strengthenedby a plurality of stiffening rings 40 spaced vertically from each other.Each ring 40 is located around the outside of blast furnace shell 10 andis radially spaced therefrom. Each stiffening ring 40 is attached toshell 10 by a plurality of circumferentially spaced bracket means 44.Referring to FIGS. 2 and 14, each stiffening ring 40 includes ahorizontally disposed web portion 41, a vertically disposed inner flangeportion 42 and a vertically disposed outer flange portion 43.

The stiffening rings 41 may also serve as catwalks around the exteriorof the furnace, and, in this connection, attached to outer flange 43 ofstiffening ring 40 is a post 39 to which rails (not shown) may beattached.

Each bracket means 44 is a vertically disposed plate having an innermostvertical edge 45 fixed to the outside of blast furnace shell 10 toattach stiffening ring 40 to the shell along, relatively, a verticalline. Inner vertical flange 42 of the stiffen ing ring is separated fromthe shell, e.g. shell stack section 20 in FIG. 2, by a space 46.

The vertical line attachment of stiffening ring 40 to shell and thespacing of the ring from the shell permit the shell to expand andcontract, relative to stiffening ring 40, between the contractedposition shown in full lines at in FIG. 2 and the expanded positionshown in dotted lines at 47 in FIG. 2. The expansion and contractiontakes place between adjacent bracket means 44 and occurs withoutpermanently deforming the shell.

Referring to FIG. 14, located near the top of shell stack section 20 isa sprinkler pipe 48 from which a cooling fluid, such as water, issprinkled onto shell 10 to trickle downwardly along the outside of theshell. Because stiffening rings 40 are spaced from the outside of theshell, the cooling fluid trickles downwardly, continuously, withoutinterruption along the outside of the shell from above a stiffening ringto below the stiffening ring, through the space 46 between thestiffening ring and the outside of the shell, around substantially theentire periphery of the shell; and the flow of cooling fluid iscontinuous, without interruption from the upper part of stack section 20to at least the lower part of bosh section 21 around substantially theentire periphery of the shell.

As shown in FIG. I, located alongside shell hearth section 22 are aplurality of cooling fluid sprinkler pipes 49 for cooling the hearthsection. Near the bottom of the bosh and hearth sections are troughs 52for collecting cooling fluid trickling down along the outside of thefurnace shell.

Another type of external cooling device, water jacket 50, is shown inFIG. 1 above tuyere 23. The water jacket extends all the way around theperiphery of the furnace. Water jackets may be located anywhere alongthe vertical dimension of the shell and are not restricted to thelocation above tuy ere 23.

The interior of a blast furnace having a shell in accordance with thepresent invention may be lined with conventional refractory materialwithout the provision of internal cooling means for the refractorymaterial; or the interior of the blast furnace may include metallicstaves 17 (FIG. 14) provided with cooling fluid conduits as disclosed inRosenak U.S. Pat. No. 3,3l4,668 or as described subsequently herein; orthe refractory material lining the interior of the furnace may be cooledby conventional copper cooling plates 51 (FIG. 7).

The thickness of and type of support for refractory lining ll of stacksection 20 depends upon the presence or absence of internal coolingstructure. If the interior of the blast furnace contain metallic coolingstaves, not only may the refractory lining be relatively thin but it mayalso be supported by the staves as described subsequently herein. If therefractory material is cooled with conventional copper cooling plates(FIG. 7), the copper cooling plates provide support for the refractorylining. If there is no provision for internal cooling in the blastfurnace, the refractory lining must be relatively thick, and therefractory material 11 in stack section 20 may be supported by aringlike bracket 60 extending around the interior of the furnace at thebottom of stack section 20 (FIG. 8).

Where the inward taper of bosh section 21 has a relatively large angle,as in embodiment 32 in FIG. 5, refractory lining 11 in stack section 20is supported from below by bosh section shell 21.

When internal cooling is to be used in conjunction with onepiece shell10, it is more desirable to use metallic cooling staves such as 17 (FIG.14) rather than conventional copper cooling plates 51 (FIG. 7). This isbecause copper cooling plates extend through relatively large holes inthe shell which are more difficult to seal than are the relatively smallshell holes required by metallic cooling staves, as will be subsequentlydescribed.

By eliminating the major discontinuity in the shell at the junction ofthe stack section and bosh section, the major location of gas leakage iseliminated. By reducing other locations where gas leakage from thefurnace interior has been a problem, the ideal of an absolutely gastightshell is much closer to reality.

Because a blast furnace having a one-piece, selfssupporting shell 10does not require or utilize a mantle or columns, it is more economicalto construct than conventional blast furnaces, and fabrication andinstallation of the furnace are simplified.

Because of the integral, one-piece construction, a hole in shell 10caused by a furnace breakout, for example, would not endanger thestructural integrity of the shell so much as would be the case if theshell were not of one-piece, integral construction. A much more sizeablehole would be required before the shell would be structurally unsafethan would be the case if the shell were not of integral, one-piececonstruction.

Referring now to the embodiment illustrated in FIGS. 9 and 10, locatedinwardly of a blast furnace shell 210 is a metallic lining extendingcontinuously from the top of the stack section 220 to the lower part ofthe bosh section 221 and comprising a plurality of vertically stackedtiers each including a plurality of circumferentially arranged staves.The staves comprise, in vertically descending sequence, upper stacksection staves 71, intermediate stack section staves 72, lower stacksection staves 73 and bosh section staves 74. Located just above upperstack section staves 71 is an impact and wear absorbing ring comprisingcircumferentially arranged wear plates 14, previously described.

All of staves 71, 72, 73, 74 are fluid cooled and are composed of castiron. The furnace is thus provided with a fluidcooled metallic liningspaced inwardly of outer shell 210 and extending continuously, withoutinterruption from the upper part of the stack section of the furnace tothe lower part of the bosh section of the furnace.

The interior diameter of the blast furnace at the wear plates issubstantially narrower than in the stack section therebelow to preventexcessive cooling in the space defined by wear plates 14 and to providebetter control over material distribution into the furnace.

The inner surface of upper stack section stave 71 gradually curves alonga vertical dimension from stack section 220 toward wear plate 14 toprovide a smooth transition in the furnace interior from a relativelythin furnace wall at the stack section to the thicker wall at thehanging stock line defined by wear plates 14.

Lower stack section stave 73 has an inner surface gradually curvingalong a vertical dimension at the junction of the stack section and thebosh section to provide a smooth transition in the furnace interiorbetween the furnace stack section and the furnace bosh section. Thissmooth transition from the stack section to the bosh section eliminatessudden changes of direction by the descending burden, the sudden changebeing an undesirable occurrence because it increases wear and causessevere changes in the interior furnace lines.

The lower part of bosh section stave 74 has an inner surface graduallycurving along a vertical dimension from the previously describedtransition portion, at the junction of the stack and bosh sections,toward a hearth section 75 of the furnace interior. The curvature istoward bosh section 221 of the furnace shell; and, by thus curving,rather than by following the slope at the top of bosh section stave 74,the furnace interior is provided with a larger diameter at the bottom ofthe bosh section than it would otherwise have. This curvature alsopermits a larger internal diameter for interior hearth section 75 whichconventionally extends vertically downwardly from the bottom of the boshsection of the furnace interior.

All of the staves 71-74 are covered with a thin lining, e.g. about 4inches, of castible refractory 76 supported by the staves. A thinrefractory lining is permissible because the staves are fluid cooled.Conventional thick refractory brick linings are eliminated.

Because the refractory is so thin, even if the refractory lining is wornaway, the interior lines of the furnace are essentially the same. Inother words, the furnace interior lines are essentially permanent. Thus,the furnace can be built initially with optimum lines, and these optimumlines are maintained during the entire time the furnace is operated.

The relatively thin refractory lining 76 also provides the furnace witha maximum interior volume for a given external diameter.

Not only the stack section but, also the bosh section of the furnaceinterior is cooled; and the thin castible refractory has a thicknesswhich is essentially uniform from the top of the cooled metallic liningto the bottom thereof.

Each of the staves is movably mounted to accommodate radial movement ofthe metallic lining relative to the furnace shell during operation ofthe furnace. This mounting is illustrated in FIG. 1 1.

A typical stave, e.g. intermediate stack section stave 72, includes arecess 84 from which an opening 85 extends through the stave. The recess84 receives the head of a bolt 86 extending through opening 85 andthrough a relatively small aligned opening 87 in shell 210 of the blastfurnace. On the outside of the shell, bolt 86 is secured in place by awasher 88 and nut 89. A gastight seal is provided around shell opening87 and comprises a tubular portion 90, the inner end of which is securedto shell 210, as by welding, and the outer end of which is closed by acap 91. The staves are spaced slightly inwardly of shell 210, and thespace between shell 210 and the staves is filled by a compressibleresilient material 92 such as polyurethane foam, glass fiber, or thelike.

As shown in FIG. 11 the top of each stave has a projection 83 receivedin a notch 82 in the bottom of the stave located thereabove. Thisnotch-projection arrangement is also provided between upper stacksection stave 71 and the bottom of wear plate 14. Wear plate 14 issuspended by a hook portion 80, at the top of the wear plate, engaging abracket 81 attached to the interior of the furnace shell. Behind wearplate I4 a layer of castible refractory material 77 extending downwardlybehind a portion of upper stack section stave 71. Wear plate 14 ismounted for vertical movement to accommodate vertical expansion of thewear plate and the underlying staves in response to thermal changes inthe furnace interior, and this is described more fully in Slagley US.Pat. No. 3,202,407.

Referring to FIG. 13, each stave is provided with internal cooling coils95 into which a cooling fluid, such as water, is introduced through aninlet conduit 96 and from which fluid is removed through an outletconduit 97. As shown in FIG. 11, inlet and outlet conduits 96, 97 extendthrough respective openings 98 in furnace shell 210 and communicate withan external cooling fluid source (not shown).

Shell opening 98 is sealed with an arrangement comprising an accordionpleated, stainless steel expansion tube 99, the inner end of which issecured to a ring 100 in turn secured to shell 210. The outer end ofaccordion pleated tube 99 is closed by a cap 101 through which conduit96 extends. The entire arrangement is gastight. Accordion pleated tube99 permits conduit 96 to move inwardly and outwardly through shellopening 98 in response to similar movement by stave 72.

Insulating material 92, between furnace shell 210 and the staves formingthe internal metallic lining of the furnace, thermally insulates theshell from the internal lining.

Referring to FIGS. 12 and 13, each of the staves 7'l-74 has a pluralityof respective projections extending inwardly from the staves forperforming a wear resisting function, now to be described.

Referring initially to FIG. 13, each upper stack section stave 71 has aseries of horizontal and vertical ridges arranged in a grid and defininga multiplicity of boxes or recesses 105. The charge materials adjacentstaves 71 are not heated to a high enough temperature to become stickyand will not build up on or stick to the surface of the staves. Theboxes 105 will trap some of this charge material, and the descendingcharge will wear against the trapped charge material. In effect, thecharge material is wearing upon itself rather than upon the staves.

The condition of the charge material adjacent staves 71 is such thatthere is relatively little wear on these staves. Most failures inconventional furnace linings in this upper part of the furnace are dueto severe temperature changes when the level of the charge materialchanges. The fluid-cooled staves described herein and constructed inaccordance with embodiments of the present invention are able totolerate these temperature changes.

Each intermediate stack section stave 72 includes a multiplicity ofcleats or protrusions 106. The charge material adjacent theseintermediate staves is heated to a relatively high temperature and issticky or tacky, although not liquid. Cleats 106 constitute anchors forthe sticky charge material so that charge material will either adhere tothe cleats or will be slowed down as it moves past the cleat-containingstaves, thereby reducing or eliminating wear on the interior surface ofa stave 72.

The same type of cleats 106 may also be provided on the upper part oflower stack section stave 73; but the lower part of stave 73 and all ofbosh section stave 74 have protrusions in the form of horizontallyextending ledges or ridges 107 (FIG. 12). Adjacent these ledges 107, thefurnace contains liquid slag. Ledges 107 assist in freezing andretaining the liquid slag to provide a self-replenishing protective wearface on the staves. The thickness of the protective covering of slag mayvary from one inch to four inches depending upon furnace conditions.Ledges 107 not only aid in building a slag wear face on the innersurface of the staves but also provide breaking lines along which theslag will peel if it breaks away from the staves, thus causing the slagto break off in relatively small sections which expose less interiorsurface of the stave than if the slag broke off in large sections. Inlieu of horizontal ledges 107, the same function could be performed byhorizontally extending corrugations.

Located between stack shell section 220 and lower stack section stave 73is a layer of castible refractory 112 (FIG. 10); and located betweenbosh section stave 74 and bosh shell section 221 is another layer ofcastible refractory material 113. Refractory layers 112, 113 helpmaintain staves 73, 74 in position and provide additional protection incase of a stave failure. As shown in FIG. 10, located inwardly of shellhearth section 222 is a lining of refractory brick 111.

In the embodiment illustrated in FIGS. 9 and 10, the furnace is depictedas having a shell 210 of conventional construction with a mantle 211 atthe junction of shell stack section 220 and shell bosh section 221. Inthis embodiment, the stack section staves 71, 72 are supported invertically descending order by the stave therebelow, an d lower stacksection stave 73 is attached to a bracket resting on mantle 2 l 1Fluid-cooled metallic linings for blast furnaces in accordance with thepresent invention may also be used with an integral, continuous,one-piece, self-supporting blast furnace shell 10 such as thatillustrated in FIG. I. In such a case, the entire support for theinternal metallic lining would be only the blast furnace shell itself,the support being performed by bolts such as 86 (FIG. 11). Afluid-cooled metallic lining extending from the top of the stack sectionto the lower part of the bosh section is shown in FIG. 1, said stavesbeing numbered 17 in the stack section and 18 in the bosh section.

The foregoing detailed description has been given for clearness ofunderstanding only and no unnecessary limitations should be understoodtherefrom as modifications will be obvious to those skilled in the art.

We claim:

1. A metallic blast furnace shell having a load-bearing superstructurecontiguous to and supported by said shell, said shell being composed ofsteel and comprising;

in vertically descending sequence, a stack section, a bosh section and ahearth section, all joined together to form an integral, continuous,uninterrupted, one-piece blast furnace shell composed of said threeshell sections;

said blast furnace shell being self-supporting and serving as the solemeans for supporting said load-bearing superstructure;

said shell having opposed sidewalls which are in nonparallel relationfor at least a portion of the vertical dimension of the shell;

the sole support for said stack section consisting of the shell sectionslocated below the stack section;

each of said lower shell sections comprising means for imparting to saidshell section sufficient strength to support the shell sections locatedthereabove and means for maintaining said strength during operation ofthe blast furnace; said strength imparting means comprising verticallyextending stiffening means extending vertically along the outside ofsaid shell upwardly from the bottom of said hearth section.

2. In a blast furnace shellas recited in claim 1 wherein said strengthimparting means comprise elongated members.

3. In a blast furnace shell as recited in claim 1 wherein said elongatedmembers comprise stiffener bars.

4. In a blast furnace shell as recited in claim 1, the junction of thestack section and bosh section being continuous, uninterrupted anddevoid of an expansion joint.

5. In a blast furnace shell as recited in claim 4, said shell comprisinga first transition portion gradually changing laterally along a verticaldimension at the junction of the stack section and the bosh section.

6. In a blast furnace as recited in claim 5, said shell comprising asecond transition portion gradually changing laterally along a verticaldimension at the junction of the bosh section and the hearth section.

7. In a blast furnace shell as recited in claim 1, the sole support forsaid stack section consisting of the shell sections located below thestack section, whereby said blast furnace shell is devoid of a mantlefor supporting the stack section and of columns for supporting saidmantle.

8. In combination with the blast furnace shell of claim 1:

a stack section refractory lining located inwardly of the stack sectionof the shell;

a bosh section refractory lining located inwardly of the bosh section ofthe shell;

and means independent of the bosh section refractory lining forsupporting said stack section refractory lining.

9. In a blast furnace shell as recited in claim 1:

a stiffening ring located around the outside of said shell and radiallyspaced therefrom;

a plurality of circumferentially spaced bracket means attaching saidstiffening ring to said shell;

said bracket means comprising means for permitting the shell to expandand contract, relative to the stiffening ring, between said bracketmeans without permanently deforming the shell.

10. In a blast furnace shell as recited in claim 9, each of said bracketmeans comprising a vertically disposed plate having vertical edge meansfixed to the outside of the shell to attach the stiffening ring to theshell along, relatively, a vertical line.

1 I. In a blast furnace shell as recited in claim 1:

a stiffening ring located around the outside of said shell and radiallyspaced therefrom;

a plurality of circumferentially spaced bracket means attaching saidstiffening ring to said shell;

and means for trickling cooling fluid downwardly, continuously, withoutinterruption along the outside of said shell from an upper locationabove said stiffening ring to a lower location below the stiffeningring, through the space between the stiffening ring and the outside ofthe shell, around substantially the entire periphery of the shell.

12. In a blast furnace shell as recited in claim 1, means for tricklingcooling fluid downwardly, continuously, without interruption along theoutside of said shell from a location at the upper part of the stacksection to a location at the lower part of the bosh section, aroundsubstantially the entire periphery of the shell.

1. A metallic blast furnace shell having a load-bearing superstructure contiguous to and supported by said shell, said shell being composed of steel and comprising; in vertically descending sequence, a stack section, a bosh section and a hearth section, all joined together to form an integral, continuous, uninterrupted, one-piece blast furnace shell composed of said three shell sections; said blast furnace shell being self-supporting and serving as the sole means for supporting said load-bearing superstructure; said shell having opposed sidewalls which are in nonparallel relation for at least a portion of the vertical dimension of the shell; the sole support for said stack section consisting of the shell sections located below the stack section; each of said lower shell sections comprising means for imparting to said shell section sufficient strength to support the shell sections located thereabove and means for maintaining said strength during operation of the blast furnace; said strength imparting means comprising vertically extending stiffening means extending vertically along the outside of said shell upwardly from the bottom of said hearth section.
 2. In a blast furnace shell as recited in claim 1 wherein said strength imparting means comprise elongated members.
 3. In a blast furnace shell as recited in claim 1 wherein said elongated members comprise stiffener bars.
 4. In a blast furnace shell as recited in claim 1, the junction of the stack section and bosh section being continuous, uninterrupted and devoid of an expansion joint.
 5. In a blast furnace shell as recited in claim 4, said shell comprising a first transition portion gradually changing laterally along a vertical dimension at the junction of the stack section and the bosh section.
 6. In a blast furnace as recited in claim 5, said shell comprising a second transition portion gradually changing laterally along a vertical dimension at the junction of the bosh section and the hearth section.
 7. In a blast furnace shell as recited in claim 1, the sole support for said stack section consisting of the shell sections located below the stack section, whereby said blast furnace shell is devoid of a mantle for supporting the stack section and of columns for supporting said mantle.
 8. In combination with the blast furnace shell of claim 1: a stack section refractory lining located inwardly of the stack section of the shell; a bosh section refRactory lining located inwardly of the bosh section of the shell; and means independent of the bosh section refractory lining for supporting said stack section refractory lining.
 9. In a blast furnace shell as recited in claim 1: a stiffening ring located around the outside of said shell and radially spaced therefrom; a plurality of circumferentially spaced bracket means attaching said stiffening ring to said shell; said bracket means comprising means for permitting the shell to expand and contract, relative to the stiffening ring, between said bracket means without permanently deforming the shell.
 10. In a blast furnace shell as recited in claim 9, each of said bracket means comprising a vertically disposed plate having vertical edge means fixed to the outside of the shell to attach the stiffening ring to the shell along, relatively, a vertical line.
 11. In a blast furnace shell as recited in claim 1: a stiffening ring located around the outside of said shell and radially spaced therefrom; a plurality of circumferentially spaced bracket means attaching said stiffening ring to said shell; and means for trickling cooling fluid downwardly, continuously, without interruption along the outside of said shell from an upper location above said stiffening ring to a lower location below the stiffening ring, through the space between the stiffening ring and the outside of the shell, around substantially the entire periphery of the shell.
 12. In a blast furnace shell as recited in claim 1, means for trickling cooling fluid downwardly, continuously, without interruption along the outside of said shell from a location at the upper part of the stack section to a location at the lower part of the bosh section, around substantially the entire periphery of the shell. 